The two largest racial/ethnic minorities in the U.S., African-Americans and Hispanics, are at higher risk for diabetes and certain diabetes complications than non-Hispanic whites. Recently, cognitive impairment and accelerated cognitive decline have been found to be higher in persons with type 2 diabetes than in nondiabetics. In population based studies these minority groups also appear to be greater risk for cognitive impairment and dementia. The relationship between race/ethnicity and cognitive impairment among persons with type 2 diabetes has not been studied. Before such studies can be undertaken, it is necessary to identify a set of cognitive function tests that is reliable and cross culturally valid in patient groups at greatest risk for type 2 diabetes. The purpose of this study is to test the hypothesis that a brief battery of culturally neutral cognitive function tests can yield reliable and valid measures of specific cognitive function domains in low literacy, bilingual, bi-cultural patient populations. The cognitive function tests included in the battery have been previously tested and normed in both English-speaking and Spanish-speaking groups, but their crosscultural validity is not known. A total of 480 patients with type 2 diabetes representing four ethnicity/language preference groups will be recruited from a large, urban, primary care clinic network (120 non-Hispanic whites, 120 non-Hispanic African-Americans, 120 Hispanics whose preferred language is English, and 120 Hispanics whose preferred language is Spanish). They will be tested at an initial time point and one month later. Patients will be compensated financially for their time so that at least 312 (65%) patients with complete test-retest data will be available for analysis. Sociodemographic and medical history data will be collected from the participants and their medical records. Height, weight, blood pressure, and waist circumference will be measured before the initial test session. In a 40% subsample (n=208), fasting plasma glucose and insulin, lipid profile, plasma homocysteine (with folate and vitamin B12), and c-reactive protein will be measured. The test-retest reliability of the individual tests in the battery will be calculated for each ethnic group, and the validity of the tests across the four defined racial/ethnic and linguistic groups will be tested using exploratory and confirmatory factor analysis. For those cognitive function measures found to be reliable and valid, multiple regression analysis will be used to test associations between test scores and specific clinical characteristics of the patients, such as age, duration of diabetes, glycemic level, diabetes treatment regimen, and each of the physical and biochemical variables will be examined.